GitHub PR Slack Bot

A lightweight Slack bot that keeps your team's pull request activity visible without leaving Slack.

When a PR is opened it posts a message to your channel. As the PR progresses, the bot reacts to that message with emoji to reflect its state. When the PR is merged or closed, the message is deleted automatically.

Reactions

Emoji	Meaning
✅ white_check_mark	PR has at least one approval
🐰 rabbit	Changes have been requested

Both emoji are configurable — swap them for any standard or custom Slack emoji.

Slash commands (mention the bot in any channel it's in)

Command	Response
@bot open prs	All open PRs with their current status
@bot needs review	PRs with no approvals yet
@bot approved	PRs with at least one approval
@bot oldest	The oldest open PR without a review

---

Setup

1. Create a Slack app

1. Go to api.slack.com/apps → Create New App → From scratch
2. OAuth & Permissions → Bot Token Scopes — add:
   • chat:write, chat:delete, reactions:write, reactions:read
   • app_mentions:read, channels:history
3. Install the app to your workspace and copy the Bot User OAuth Token (xoxb-...)
4. Copy the Signing Secret from Basic Information

2. Deploy to Railway

1. Fork this repo
2. Go to railway.app → New Project → Deploy from GitHub repo
3. Select your fork, set the root directory to /
4. Add all variables from .env.example under Variables
5. Add a Volume mounted at /app/data to persist PR state across deploys
6. Copy the public Railway URL — you'll need it for the next steps

3. Connect Slack Events

In your Slack app settings:

1. Event Subscriptions → enable, set Request URL to:

   https://your-railway-url.railway.app/slack/events
   

2. Subscribe to bot events: app_mention
3. Save changes and reinstall the app if prompted

4. Add a GitHub Webhook

In your GitHub repo → Settings → Webhooks → Add webhook:

• Payload URL: https://your-railway-url.railway.app/github/webhook
• Content type: application/json
• Secret: the value you set for GITHUB_WEBHOOK_SECRET
• Events: select Pull requests and Pull request reviews

5. Invite the bot to your channel

/invite @your-bot-name

---

Configuration

All configuration is done through environment variables. See .env.example for the full list.

Variable	Required	Default	Description
SLACK_BOT_TOKEN	✅	—	Bot token (xoxb-...)
SLACK_SIGNING_SECRET	✅	—	From Slack app Basic Information
SLACK_CHANNEL_ID	✅	—	Channel to post PR messages in
GITHUB_TOKEN	✅	—	Personal access token (repo, read:org)
GITHUB_WEBHOOK_SECRET	✅	—	Secret set on the GitHub webhook
GITHUB_REPO_OWNER	✅	—	GitHub org or username
GITHUB_REPO_NAME	✅	—	Repository name
EMOJI_APPROVED	—	white_check_mark	Reaction emoji for approvals
EMOJI_CHANGES_REQUESTED	—	rabbit	Reaction emoji for changes requested
MENTION_PREFIX	—	<!here>	Prefix on PR messages (<!channel>, empty to disable)

---

Running locally

npm install
cp .env.example .env   # fill in your values
npm run dev

Use ngrok to expose your local server for Slack and GitHub webhooks during development:

ngrok http 3000

Set both webhook URLs to your ngrok URL while testing.

---

How it works

• PR opened/reopened → bot posts to Slack, stores the message timestamp
• PR review approved → adds ✅, removes 🐰
• PR changes requested → adds 🐰, removes ✅ if no other approvals remain
• PR review dismissed → re-evaluates and removes ✅ if no approvals remain
• New commits pushed → clears approvals, removes ✅ (mirrors GitHub's stale review behaviour)
• PR merged or closed → deletes the Slack message

State is persisted to data/store.json. Mount a Railway Volume at /app/data to survive redeploys.

---

License

MIT